Organ reed pipe



Feb. 7, 1961 BOLTON 2,970,507

ORGAN REED PIPE Filed Nov. 10, 1958 United States Patent ORGAN REED PIPERalph E. Bolton, deceased, late of Weston, Mass., by

l'ivelyn M. Bolton, administratrix, Weston, Mass., asslgnor toAeolian-Skinner Organ Company, Inc., South Boston, Mass., a corporationof Massachusetts Filed Nov. 10, 1958, Ser. No. 772,832

Claims. (Cl. 84-350) This invention relates to pipe organs and moreparticularly to the tone generators adapted to be associated with reedpipes in such musical instruments.

The tone generator in an organ reed pipe is the combination of a shallothaving a flat surface with a longitudinal aperture therein and a reedtongue which is positioned over the aperture in this shallot. This reedtongue is a sheet of brass, or other suitable material, which heretoforehas been carefully voiced by imparting to that tongue a critical degreeof curvature. When the reed is vibrating under influence of a flow ofair it rolls down smoothly against the shallot surface. Both the propercurve and the absolute smoothness of that curve are essential in orderto produce the desired tone. Should a flat spot occur in the reed byreason of an imperfect curve a harsh and blatant tone will be produced.Thus the proper manufacture of the reed pipe has depended to asubstantial extent on the proper voicing or curving of the reed tongue.This is accomplished manually by a voicer who utilizes a burnishing tooland a shaped block of polished steel to impart a smooth curvature to thetongue. This hand voicing operation, in addition to demanding aconsiderable degree of skill, is a time consuming operation. Forexample, a full day is commonly required to properly voice a reed tonguefor the 32 Contre Bombarde pipe.

Accordingly, it is an object of this invention to provide a reed pipetone generating element which may be manufactured more inexpensively andby mechanical methods.

Another object of the invention is to provide a tone generator includinga shaped shallot which is capable of producing a quality of tone equalor superior to that obtained by the prior art reed voicing method.

A further object of the invention is to produce a more versatile tonegenerator for the reed pipes.

In the reed pipe according to the preferred embodiment of the inventionthe tone generator includes the combination of a fiat reed tongue and ashallot which has a cooperating curved surface precisely curved inaccordance with a mathematical equation. A simple curve thus may beprovided on the shallot surface which cooperates with the reed tongue ina manner to attain a tone generating instrument of the desired quality.Thiscurve of the shallot surface is unique and is not the same curveheretofore imparted to the reed tongue. Among the advantages of theconstruction is that the tone generators may be manufactured bymechanical methods, thereby increasing production and reducing overallcost. Further the exclusive reliance on the skill of the voicer for thiscritical step in the manufacture of the reed pipe is eliminated. Inaddition the proper curvature of the reeds was dependent on the windpressure whereas in apparatus constructed according to the invention thesingle curve is correct for a wide variety of wind pressures. A reedpipe utilizing a shallot curved according to the invention also providesa brighter tone than do comparable prior art pipes.

Other objects and advantages of the invention will Patented Feb. 7, 1961ice 2 be seen as the following description of the preferred embodimentof the invention progresses, in conjunction with the drawing, in which:

Fig. 1 is a view of the reed pipe assembly, in partial section,incorporating the tone generating apparatus according to the preferredembodiment of the invention;

Fig. 2 is a sectional view along the line 2-2 of- Fig. 1; v

Fig. 3 is a top view of the shallot according to the preferredembodiment of the invention;

Fig. 4 is a top view of the reed according to the preferred embodimentof the invention;

Fig. 5 is a sectional side view of the reed and shallot mounted in theblock of an organ reed pipe; and

Fig. 6 is a graphical representation of the curve given to the shallotaccording to the preferred embodiment of the invention.

A view of the assembly of a typical reed pipe for an organ is shown inFig. l. The assembly includes a horn or resonator 10, a cylindrical orconical structure which may have a variety of shapes and endterminations. A slot 12 of adjustable length or other suitable means isprovided near the top of the horn in order that the effective resonatinglength of the horn may be changed. The lower end of the horn is securedto a block 14 of dense material, such as lead, by suitable means, forexample, soldering. This block is bored to provide a pas sageway 16which communicates with the interior of the horn 10. The configurationof the passageway 16 in the block is shown in Fig. 2.

The sound generating apparatus comprises a shallot 18 and a reed tongue20. The shallot, shown in Fig. 3, is a tube of brass or other suitablematerial, open at one end and closed at the other end. There are twoprincipal shapes of the shallot, the French shallot which is asubstantially cylindrical tube and has a rounded end, and the Englishand German shallots, a tapered or conical tube which is closed at oneend by a flat plate. Although the invention is not limited to one typeof shallot, the shallot which will be described is of the' French type.One surface 22 of the shallot is flattened and a longitudinal aperture24 is exposed in that surface. This aperture extends from apoint closelyadjacent the closed end of the shallot towards the open end.

The reed tongue 20, shown in Fig. 4, is positioned over the aperture 24.There is a relative curvature between the reed and the shallot surface,and the reed, when flexed, is adapted to contact the shallot surface atthe edges of the aperture to substantially close the aperture.Heretofore the reed tongue 26 has been curved, or voiced, substantiallyas shown by the dotted line in Fig. 5, and has cooperated with astraight shallot surface.

The shallot 18 and reed tongue 20 are mounted together and inserted intothe passageway 16 by press-fit. A wedge 26 is inserted into the slot 28provided in the passageway 16 to positively secure the reed tongue inposition. A tuning rod 30 passes through the aperture 32 in block 14 andhas a tip end 34 which is adapted to contact the reed tongue. The rod 30may be adjusted longitudinally of the tongue, thereby aifording controlof the eifective vibrating length of the tongue.

A boot 36, commonly manufactured of zinc, pipe metal, or wood, isinserted over the positioned shallot and tongue and is secured to theblock 14 by cooperation of the conforming tapered surfaces thereof. Theboot has an aperture 38 in its lower end through which air is admittedas desired. Sound is produced by passing air across the reed tongue 20and through the aperture 24 and the shallot. The pressure differentialon the reed tongue tends to cause it to roll smoothly down the shallotsurface substantially closing the aperture and changing the pressuredifferential. The tongue then tends to return toward and past itsinitial position and the action is repeated alternately to close andopen the aperture. This movement of the tongue in cooperation with theshallot generates the desired tone, which tone isthen amplified andmodified by the resonator.

The organ pipe according to the invention includes a shallot in whichthe surface adjacent aperture 24 is curved rather than straight. In thepreferred embodiment, a flat unvoiced reed tongue 20 cooperates withthis surface. The curve of the shallot surface is distinct from thecurve heretofore imparted to the reed by the voicer in an exacting andtime consuming operation. That curve heretofore has been obtained by amanual operation with complete reliance on the skill and the ear of theartisan. The dimensions of that curve were not of concern to thevoicers. In contrast, the shallot surface, provided in accordance withthe inventIon, is a precise curve which is described with substantialaccuracy by the following exponential equation:

substantially as is shown in Fig. 6. Shallots curved in accordance withthis equation, in cooperation with flat reeds, produce ideal tones forthe chorus reeds in the 32 foot Contre Bombarde series, for example.Modification of that curve, as defined by the equation:

specifies a lower limit of acceptability and the following equationdefines an upper limit of acceptability:

These equations define the curve of the shallot surface between X and Swhere S is the length of the shallot. In these equations L is the lengthof the pipe. Along the shallot surface from X equal to 0 (the open endof the shallot) to X equal to X Y equals 0. Thus the curve of theshallot surface is the combination of a straight line and an exponentialcurve. While the constant X varies somewhat it is generallyapproximately equal to It is to be noted that the curved plane surfaceof the shallot produces an aperture not of constant width, but ofincreasing width toward the closed end of the shallot. The shallotsurface may be easily, quickly and accurately shaped in accordance withthis equation in an appropriately controlled mechanical grindingoperation. A slight amount of hand finishing is sometimes desirable inorder to obtain the exact tone color sought for the particularapplication of the organ in which the reed pipe is used.

Thus the invention provides an improved organ reed pipe which may bebuilt in accordance with certain modern manufacturing techniques, morerapidly and at significantly reduced cost. The pipe constructedaccording to the invention produces a tone equal, if not superior, intone quality to the best prior art pipe. The invention, in addition,provides a construction which is substantially more versatile than thoseheretofore used in the pipe organ art.

While the preferred embodiment of the invention has i been shown anddescribed it will be understood that the invention is not intended to belimited thereto or to details thereof and departures may be madetherefrom within the spirit and scope of the invention as defined in theclaims.

Whatis claimed is:

1. In an organ reed pipe, a sound generating apparatus comprising a reedtongue adapted to be vibrated by air pressure, and a shallot open at oneend and having a longitudinal aperture cut through a'portion of the wallthereof, said aperture having edge portions which define a smothlycurved plane surface, the curve of said surface being defined by theequation:

said reed tongue being adapted to be secured in position relative tosaid surface such that it overlies the edge portions of said apertureand is adapted to roll down smooth- 1y into progressive abutment withsaid edge portions when it is vibrated.

2. The apparatus as claimed in claim 1 wherein said shallot is a tubeclosed at one end and said aperture is positioned in a curved planesurface portion of said shallot, said surface portion being curvedsmoothly along the length of the shallot such that it approaches theaxis of the shallot adjacent the closed end thereof.

3. The apparatus as claimed in claim 1 wherein said reed tongue is asubstantially flat flexible member.

4. An organ reed pipe having a musical tone generator comprising avibratory reed tongue, a shallot having a closed end, an open end and aninterior passageway, said shallot being substantially circular incross-section but with a portion of said cross-section defining a flatsurface adapted to receive said reed tongue in cooperating relationship,said surface being formed in a plane curve which approaches the axis ofthe shallot adjacent said closed end, and having an aperture in saidsurface such that communication is provided from outside said shallotand means to position said reed tongue on said surface such that ittends to roll down smoothly against said surface under the influence ofair pressure to control the flow of air through the said passageway toproduce the desired tone. 7

5. The organ reed pipe as claimed in claim 4 wherein the curve of saidsurface is defined by the equation:

References Cited in the file of this patent UNITED STATES PATENTS357,469 Davis Feb. 8, 1887 795,493 Ditto July 25, 1905 1,323,436 AustinDec. 2, 1919 1,363,580 Fletcher Dec. 28, 1920

